Comparative study of the repair of cracked plates with two different composite patches

The purpose of this study is to analyze the behavior of a crack with and without reinforcement by a composite patch of an aluminum plate in mode I using the finite element method. The repair patch is boron / epoxy and Carbon / epoxy, which are used with great success by many researchers For the distribution of the stresses according to the various loadings, we can conclude that the effect of repair by patch in composite is very distinct, considering the intensities of stresses which decrease for each repair corresponding to the plate not repaired, therefore, the patch in composite dampens the stress field induced at the crack tip and causes a reduction in stresses. The repair with the Bore / epoxy composite patch is more effective than the Carbon/Epoxy patch, this is due to the mechanical properties and the various characteristics specific to boron/Epoxy which gives very significant and very effective results for the repai

Study of mechanical behavior by fatigue of a cracked plate repaired by different composite patches

This research is based on the study of the fatigue behavior of an aluminum alloy plate with a central crack. The plate is subjected to a tensile loading on its lower and upper parts. Several parameters were highlighted, such as the loading effect with a load ratio R = 0. The effects of the load ratio on both the repaired and not repaired plates, by two composite patches, which are boron/epoxy and graphite/epoxy, were investigated, as well as the effect of the plate material on plate life, comparing different material

Numerical simulation of a crack emanating from a micro-cavity in the orthopedic cement by technical sub modeling of total hip prosthesis

PMMA has important micro structural heterogeneities such as cavities, and its elastic behavior is greatly affected by the presence of defects that may imply its weakening and cause failure. In areas of high concentrations of stress and due to the presence of cavities, micro cracks appear after crushing cavities due to patient movements, and grow and weld to each other until they form a macro     fissure that propagates until the total removal of the prosthesis.. In this study, the existence of a crack emanating from  a cavity with a diameter of 0.7 mm was assumed; our assessment takes into account two parameters, the position of the crack in the cement and we calculated the stress intensity factor (SIF) in the proximal part of orthopedic cement

WA-GPSR: Weight-Aware GPSR-Based Routing Protocol for VANET

The extremely fast topology has created new requirements for the geographic routing protocol, which has been the most efficient solution for Vehicular Ad-hoc Networks (VANETs). The frequent disconnection of links makes the choice of the next routing node extremely difficult. Hence, an efficient routing algorithm needs to deliver the appropriate path to transfer the data packets with the most relevant quality of service (QoS). In this work, the weight-aware greedy perimeter stateless (WA-GPSR) routing protocol is presented. The enhanced GPSR protocol computes the reliable communication area and selects the next forwarding vehicle based on several routing criteria. The proposal has been evaluated and compared to Maxduration-Minangle GPSR (MM-GPSR) and traditional GPSR using strict metric analysis. Our experimental results using NS-2 and VanetMobiSim, have demonstrated that WA-GPSR has the ability to enhance network performance

A rare cause of acute esophageal necrosis: A case report

Acute esophageal necrosis (AEN) or black esophagus is a rare entity characterized by diffuse circumferential black pigmentation of the esophageal mucosa due to ischemic necrosis. It may be lethal, especially among elderly patients with multiple comorbidities and hemodynamic instability. Diagnosis is based on gastroscopy. Treatment consists of intravenous fluids, proton pump inhibitors, and additional therapies to treat the underlying illness. We report a rare case of a woman in her 50s with cervical cancer who presented with hematemesis and sepsis. Upper gastrointestinal endoscopy showed a black esophagus and an ulcerobudding duodenal process. Few days later, she developed abdominal distension with diffuse pain. Abdominal CT scan demonstrated perforation of gastroduodenal tumor. The treatment was based on resuscitation, proton pump inhibitors, antibiotics, and surgery of the perforated tumor. Unfortunately, the patient died 2 days later because of septic shock. The black esophagus is a fatal complication, thus diagnosis at an early stage and timely management may improve survival. This is the first case reported of AEN due to perforated duodenal tumor explained by septic shock leading to an ischemic esophageal injury

Association between pancreatic cancer and diabetes: insights from a retrospective cohort study

Abstract Background Studies investigating the prevalence of pancreatic cancer have revealed a heightened risk of 1.5 to 2.0 times among individuals with long-standing type 2 diabetes mellitus. Aims We aimed to estimate the prevalence of diabetes among patients with pancreatic cancer, and identify the factors associated with type 2 diabetes mellitus in this population. Methods This retrospective observational and analytical study was carried out in the Department of Gastroenterology of the Mohammed VI University Hospital over a period of 5 years, between 2018 and 2022, including all patients with confirmed cases of pancreatic adenocarcinoma. Results Out of the 197 patients, 38.1% had a history of diabetes, among them, 42.7% had new-onset diabetes, while the remaining 57.3% had long-standing diabetes. Diabetic patients were significantly older than nondiabetic patients (mean age of 67.2 vs. 63, P = 0.009). Diabetes was more prevalent among obese patients (66.7%, P = 0.01), and less frequent among individuals with chronic alcohol consumption (20% vs. 80%, P = 0.04), and tobacco smokers (24.4% vs75.6%, P = 0.03). Among patients with an ECOG score ≥ 3, DM, 54.5% were DM-patients (P = 0.033). The same significant association was found for the Nutritional Risk Index, Patients who had moderate or severe malnutrition were more likely to be diabetic 74.7% (P = 0.004). Diabetic patients were less likely to undergo surgery due to comorbidities and general health deterioration. However, no significant differences were observed in sex, tumor stage or location. Conclusion Our study has shown an increased prevalence of diabetes in pancreatic cancer and highlights the importance of considering this cancer in cases of recent onset or uncontrolled diabetes, especially in elderly individuals